FreeBSD/Linux Kernel Cross Reference
sys/fs/ntfs/ntfs_ihash.c

     /*      $NetBSD: ntfs_ihash.c,v 1.5 1999/09/30 16:56:40 jdolecek Exp $  */
     
     /*-
      * Copyright (c) 1982, 1986, 1989, 1991, 1993, 1995
      *      The Regents of the University of California.  All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      @(#)ufs_ihash.c 8.7 (Berkeley) 5/17/95
     * $FreeBSD$
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/vnode.h>
    #include <sys/malloc.h>
    #include <sys/mount.h>
    #include <sys/mutex.h>
    
    #include <fs/ntfs/ntfs.h>
    #include <fs/ntfs/ntfs_inode.h>
    #include <fs/ntfs/ntfs_ihash.h>
    
    MALLOC_DEFINE(M_NTFSNTHASH, "ntfs_nthash", "NTFS ntnode hash tables");
    
    /*
     * Structures associated with inode cacheing.
     */
    static LIST_HEAD(nthashhead, ntnode) *ntfs_nthashtbl;
    static u_long   ntfs_nthash;            /* size of hash table - 1 */
    #define NTNOHASH(device, inum)  (&ntfs_nthashtbl[(minor(device) + (inum)) & ntfs_nthash])
    static struct mtx ntfs_nthash_mtx;
    struct lock ntfs_hashlock;
    
    /*
     * Initialize inode hash table.
     */
    void
    ntfs_nthashinit()
    {
            lockinit(&ntfs_hashlock, PINOD, "ntfs_nthashlock", 0, 0);
            ntfs_nthashtbl = hashinit(desiredvnodes, M_NTFSNTHASH, &ntfs_nthash);
            mtx_init(&ntfs_nthash_mtx, "ntfs nthash", NULL, MTX_DEF);
    }
    
    /*
     * Destroy inode hash table.
     */
    void
    ntfs_nthashdestroy(void)
    {
            hashdestroy(ntfs_nthashtbl, M_NTFSNTHASH, ntfs_nthash);
            lockdestroy(&ntfs_hashlock);
            mtx_destroy(&ntfs_nthash_mtx);
    }
    
    /*
     * Use the device/inum pair to find the incore inode, and return a pointer
     * to it. If it is in core, return it, even if it is locked.
     */
    struct ntnode *
    ntfs_nthashlookup(dev, inum)
            struct cdev *dev;
            ino_t inum;
    {
            struct ntnode *ip;
    
            mtx_lock(&ntfs_nthash_mtx);
            LIST_FOREACH(ip, NTNOHASH(dev, inum), i_hash)
                    if (inum == ip->i_number && dev == ip->i_dev)
                            break;
            mtx_unlock(&ntfs_nthash_mtx);
    
            return (ip);
    }
   
   /*
    * Insert the ntnode into the hash table.
    */
   void
   ntfs_nthashins(ip)
           struct ntnode *ip;
   {
           struct nthashhead *ipp;
   
           mtx_lock(&ntfs_nthash_mtx);
           ipp = NTNOHASH(ip->i_dev, ip->i_number);
           LIST_INSERT_HEAD(ipp, ip, i_hash);
           ip->i_flag |= IN_HASHED;
           mtx_unlock(&ntfs_nthash_mtx);
   }
   
   /*
    * Remove the inode from the hash table.
    */
   void
   ntfs_nthashrem(ip)
           struct ntnode *ip;
   {
           mtx_lock(&ntfs_nthash_mtx);
           if (ip->i_flag & IN_HASHED) {
                   ip->i_flag &= ~IN_HASHED;
                   LIST_REMOVE(ip, i_hash);
           }
           mtx_unlock(&ntfs_nthash_mtx);
   }

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